Evaluation of Profiled Pavement Markings;Final rept. 13 Aug 01-13 Aug 03

摘要

This study evaluated flat thermoplastic markings (FTM) and profiled pavement markings (PPM) installed on highways maintained by the Alabama Department of Transportation. The primary objectives of this evaluation were to compare service life, life-cycle costs, crash rates, and wet-night visibility (measured by wet retroreflectivity) of the two marking types. Nighttime dry and wet retroreflectivity of sixteen one-mile segments of FTM and twenty-one one-mile segments of PPM were measured using a mobile retroreflectometer. The average dry retroreflectivity of new FTM and PPM tested by this study were 320 and 242 mcd/m2/lux, respectively. In addition, both FTM and PPM were found to lose dry retroreflectivity at similar rates with respect to CTP. As a result, under similar ADT levels, FTM consistently provides a higher dry retroreflectivity than PPM of the same age. On average, FTM was found to last six or more months longer than PPM. The average wet retroreflectivity of PPM at the end of its service life was found to be as high as the average wet retroreflectivity of FTM at the beginning of its life. However, crash data analysis did not indicate that the higher retroreflectivity of PPM resulted in a lower crash rate than FTM. The life cycle cost analysis showed that for a five-year marking service life and an eight year life cycle, the cost per mile of marking was ;1,355 for FTM and ;4,240 for PPM. Overall, the study found that economics, marking service life, and crash data do not justify widespread use of PPM in preference to FTM.